Comparison of UAV and fixed‐wing aerial application for alfalfa insect pest control: evaluating efficacy, residues, and spray quality

• Published in: Pest management science 2021-11, Vol.77 (11), p.4980-4992
• Main Authors: Li, Xuan, Giles, D Ken, Andaloro, John T, Long, Rachael, Lang, Edward B, Watson, Lawrence J, Qandah, Issa
• Format: Article
• Language: English
• Subjects: Agrochemicals; Aircraft; Alfalfa; Chemical pest control; Chemical residues; chlorantraniliprole; Commercial aircraft; Crop dusting; crop protection; Crops; deposition; Droplets; efficacy; Filter paper; Insecticides; Insects; manned agricultural airplane; Optimization; Parameters; Pest control; Pesticide application; Pesticides; Pests; Plant protection; remotely piloted aerial application systems (RPAAS); residue; Residues; Rotors; System effectiveness; unmanned aerial spraying systems (UASS); Unmanned aerial vehicles; Water purification
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.6540

BACKGROUND Integrating unmanned aerial vehicles (UAV) as a new method of pesticide application into existing commercial crop protection systems requires extensive research and comparison to conventional, proven application technology. Pest control expressed as efficacy against target pests, and spray quality expressed as coverage and chemical residue are three key criteria. We investigated and compared these quantitative parameters between a multi‐rotor UAV and conventional piloted airplanes in two commercial alfalfa production systems. RESULTS Effective and equivalent control of leaf‐feeding insect pests was achieved by both methods of aerial application when delivering chlorantraniliprole at the same labeled use rate in different spray volumes (46.8 and 93.5 L ha–1) on commercially grown alfalfa in California. Residue levels and spray coverage were also comparable and consistent between the UAV and airplane applications across three sampling techniques, specifically residue levels on alfalfa, insecticide recovery from filter paper, and spray coverage on water sensitive cards. Differences in droplet size and deposit characteristics were more variable for the UAV than airplanes based on analysis of deposition images. CONCLUSION The results of this study provide confidence supporting the use of small‐scale multi‐rotor UAVs for pesticide application on agricultural crops. According to the parameters tested, UAV application quality and crop protection performance were comparable to that of the conventional fixed wing airplane application. However, the droplet spectrum and the short‐term fate of droplets from unmanned aerial spray system require further optimization for effective and efficient crop protection with minimal risk to the environment. Performance of UAV to control lepidopteran insect pests in alfalfa using chlorantraniliprole insecticide was comparable to conventional piloted airplanes based on integration of spray deposition, residue analysis, and crop protection assessment. © 2021 Society of Chemical Industry.